Improved estimation and compensation method for orthogonal multi-carrier underwater acoustic mobile communication channel

Abstract

The invention discloses a Doppler estimation and compensation method for sparseness detection of an orthogonal multi-carrier underwater acoustic mobile communication channel. Aiming at the problem caused by limited frequency domain response resolution in a complex multipath time-varying channel environment, the method utilizes the principle that the Doppler distortion signal subcarrier orthogonality is not changed, extracts a pilot subcarrier frequency domain response by local subcarrier Discreet Fourier Transform (DFT), calculates channel impulse responses and sparseness thereof of the signalunder different Doppler compensation conditions, and selects a decompression signal of the compression factor estimation result with the largest channel sparseness, thereby realizing the mobile underwater acoustic communication in the complex multipath time-varying channel environment. The method improves the Doppler estimation accuracy, which is mainly due to the frequency domain resolution accuracy. The carrier demodulation matrix of the method is generated by calcualting a Doppler compression factor, and the Doppler is used to demodulate the carrier matrix of each subcarrier with a relatively higher resolution, so that the Doppler compensation effect is better.

Description

technical field [0001] This method involves the research on OFDM mobile communication under complex multipath and time-varying channel environment, more specifically, for the Orthogonal Frequency Division Multiplexing (OFDM) underwater acoustic mobile communication channel The sparseness detection Doppler estimation method is not effective in Doppler distortion estimation in the fast time-varying multipath channel environment. An improved channel sparsity detection Doppler estimation method is proposed for underwater acoustic mobile communication. field. Background technique [0002] The available bandwidth resources in underwater acoustic communication are very limited. OFDM technology with high spectrum utilization and good anti-multipath propagation ability has become a hot spot in underwater acoustic high data rate communication in recent years. However, OFDM is sensitive to Doppler frequency offset, especially in underwater acoustic communication with relatively low so...

AI Technical Summary

Problems solved by technology

[0005] The purpose of this method is to provide an improved orthogonal multi-carrier underwater acoustic mobile communication channel estimation and compensation method. Aiming at the problem caused by the limited frequency domain response resolution in the complex multipath time-varying channel environment, the Doppler distortion signal is used to Based on the principle of invariant subcarrier orthogonality, the local subcarrier discrete Fourier transform (Discreet FourierTransform, DFT) is used to extract the frequency domain response of the pilot subcarrier, and the channel impulse response of the signal under different Doppler compensation conditions and its Sparsity, select the compression factor estimation result with the largest channel sparsity to demodulate the signal, and realize mobile underwater acoustic communication in complex multipath time-varying channel environment

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